Opiate Overdose 💉
Emergency management of opioid overdose. Based on IAEM guideline: naloxone dosing, airway support, monitoring and disposition for NCHDs.
🔍 Clinical features
- Classic triad: apnoea or severe respiratory depression, stupor/altered consciousness, miosis (pinpoint pupils). Not always all present.
- Most reliable sign: respiratory depression (slow/shallow breathing). RR ≤12 outside physiological sleep may suggest opioid poisoning, especially with miosis and/or coma.
- Other: hypotension, decreased bowel sounds, respiratory or cardiac arrest. Consider mixed overdose (alcohol, benzodiazepines, stimulants, paracetamol, salicylates) and effect on findings.
- Context: recreational use, prescription opioids, paraphernalia, or unexplained reduced GCS. Same principles apply to therapeutic/iatrogenic overdose.
🚨 Immediate management
- Maintain clear airway and adequate ventilation; call for help; consider critical care if severely obtunded or unstable.
- Supplemental O₂; secure IV access; transfer to monitored area.
- Remove any topical opioid patches.
- IV crystalloids for hypotension; manage arrhythmias as appropriate.
- Check glucose and maintain normoglycaemia.
- Treat seizures as per local protocol.
- Aim of naloxone: reversal of respiratory depression and airway protective reflexes, not full reversal of unconsciousness. Opiate reversal is unpleasant—avoid in stable patients without respiratory compromise.
💊 Naloxone (antidote)
- Give 400 micrograms (0.4 mg) IV/IO. If no response after 1 minute, give 800 mcg (0.8 mg). If still no response after another 1 minute, give a further 800 mcg.
- If no response after 2 mg total, give a further 2 mg. Large doses (>4 mg) may be needed with potent opioids (e.g. fentanyl) or severe poisoning.
- Consider alternative diagnosis if no response to naloxone.
- If IV/IO not available or delayed: give IM or intranasal naloxone; repeat every 2–3 minutes. Monitor for recurrence of CNS and respiratory depression.
- Duration of naloxone (half-life ~30–80 min) is shorter than most opioids—repeated doses or infusion may be required.
💉 Naloxone infusion
- If repeated boluses are needed, start an infusion at ~60% of the total dose (in mcg) required to reverse respiratory depression, per hour.
- Example: if 800 mcg total was required, start at 480 mcg/hour; titrate to clinical effect. Add 4 mg naloxone (10 mL of 400 mcg/mL) to 30 mL NaCl or 5% dextrose = 100 mcg/mL; run via IV pump.
- Refer to local protocol or IAEM guideline for full infusion table (200–2000 mcg initial bolus → starting mcg/hr and mL/hr).
🔎 Investigations
- Blood glucose; VBG/ABG (electrolytes, gas abnormalities, hypoglycaemia).
- Paracetamol and salicylate levels if mixed overdose suspected.
- ECG: arrhythmias, prolonged QT, widened QRS.
- CXR if aspiration pneumonia or ARDS suspected.
- Urine toxicology as per local policy. Consider CT brain if traumatic cause for obtundation possible.
📋 Monitoring
- After adequate response: respiratory rate, SpO₂, conscious level every 15 minutes for the first hour, then every 30 minutes for the next three hours; blood gases as indicated.
- ECG, BP, SpO₂; ETCO₂ if available for respiratory rate and effectiveness of ventilation.
📤 Disposition
- Discharge: only when features of opioid toxicity have fully resolved, patient self-ventilating adequately, and no naloxone (bolus or infusion) required for at least 6 hours. Awake, alert, normal vitals and SpO₂ on room air, mobilising at baseline.
- Admission: acute lung injury, poor response to initial boluses, or need for naloxone infusion. Consider critical care review if poor response to infusion, worsening hypercapnia, or risk of airway compromise (intubation may be needed).
- Observation: 6 hours for standard-release preparations; 12 hours for controlled-release. Avoid discharging at night.
🌿 Harm reduction – Take Home Naloxone (THN)
- Consider THN for patients treated with naloxone (community or ED), self-medicating with non-prescribed opioids, high-risk use (e.g. with benzodiazepines, alcohol, or after release from prison/detox), or if patient/family request.
- If THN not available in ED, signpost to drug treatment services (e.g. services.drugs.ie). Provide education on recognising overdose and using naloxone; replacement via OST provider or community pharmacy.
- Referral to social work, inclusion health, and community supports (e.g. OST) as appropriate. Children First (2015) if welfare concerns for dependent children.